Autologous fat transfer, also known as fat grafting, has emerged as a widely used breast and facial reconstruction technique. Lipofilling, a form of fat grafting, has been used for several years, for example, to repair minor differences between a reconstructed breast and the non-reconstructed breast or to fill large dents in the body or face. Further uses include clinical applications to treat scleroderma, post-radiation skin damage, and skin rejuvenation. A surgeon performing a lipofilling procedure must go through several steps to obtain the fat cells necessary for grafting. After initial extraction by vacuum suction of raw lipoaspirate from the patient, the fat cells must be separated from the blood, debris, and oil in the lipoaspirate mixture.
One way to accomplish separation of fat cells is to allow gravity to separate out the layers naturally. This can be a slow, time-consuming process, taking approximately twenty to thirty minutes to achieve appropriate separation. Once separated, multiple syringes and other containers are employed to fully isolate the fat.
Another method to accomplish separation is by placing the suctioned fat in a cloth and squeezing the fat or allowing it to drain until the impurities are removed. This method is problematic because it is a complicated procedure, is time-consuming, and there is a greater risk of the fat cells becoming infected due to contact with the environment.
Still another method of separation is accomplished by placing the syringe in a centrifuge. The centrifuge rotates at approximately 1000 rpm for two to three minutes, allowing three layers to form: a more-dense blood and debris layer on the bottom, a desired fat cell layer in the middle, and a less-dense oil layer on top. Once separated, multiple syringes and containers must typically be employed to isolate the desired fat cells before the desired fat cells can be grafted back into the patient.
Methods of removing the oil layer from lipoaspirate solutions separated by gravity or centrifugation without the use of multiple containers and syringes remain inefficient and burdensome. The oil is trapped above the fat layer and cannot be discharged from conventional syringes or containers without prolonged effort. Each separation technique of the lipoaspirate that occurs in any of the above methods decreases the efficacy of the treatment as a whole for myriad reasons. Exposure of fat cells to potential contaminants or unnecessary trauma lead to an increase in potential infection or cell necrosis. Either of these conditions can cause serious complications in the patient or require further treatment to correct any issues. Potential risks to patient under sedation are also of concern. Typically, the longer a patient is under anesthesia, the greater the potential risk to a patient for an anesthesia-associated complication to occur.
As such, there is a need to reduce the required active steps involved in harvesting fat cells to increase the effectiveness, safety, and efficiency of the procedure. Fewer active steps would enhance the likelihood of the healthy fat cells being successfully grafted, reduce potential patient harm, and shorten the procedure to reduce the costs associated with the treatment.